One type of earplug is formed primarily of elastomeric material and has a pocket containing gas (air) that enables the earplug to be more easily compressed during insertion and to remain compressed in the ear. This enables easier insertion into a person's ear canal and reduces pressure on the walls of the ear canal to increase comfort. A method for forming an earplug with a desired molded outside shape such as with flanges, and with an internal pocket structure with enhanced noise attenuation characteristics would be of value.